1. Field of the Invention
The present invention relates to a method and apparatus for processing whole blood and more specifically to a method and apparatus for separating whole blood into its components for collection of a desired component such as platelets.
2. Description of the Prior Art
Heretofore various methods and apparatus have been proposed for processing whole blood and separating the same into the various components thereof. Such prior art methods and apparatus have involved intervivos blood processing in which whole blood is taken from a live donor, separated within a processing system into its constituent components and a desired component is segregated for collection from the donor, followed by returning the remaining blood fluid to the donor. Typically, the blood components that are separated are plasma, red blood cells, white blood cells and platelets. As will be described in greater detail, the method and apparatus of the present invention are particularly adapted for separating platelets from whole blood. Such a method or process is commonly referred to as plateletpheresis.
Methods and apparatus for carrying our intervivos blood processing that have been utilized in the past, have typically included a separation chamber within which whole blood from a donor is subjected to a centrifugal force. This is typically accomplished in a centrifuge device. Because of differences in densities the various blood components will congregate in different zones at different radial distances from the center of rotation of the separation chamber. Then, collection ports in the chamber are utilized to remove the blood components from the various zones in the separation chamber for storage or recirculation.
Heretofore such methods and devices have required a large quantity of whole blood in order to separate the whole blood into the various components thereof. Also, such previously proposed methods and apparatus have required a significant amount of time such as from 21/2 to 4 hours to obtain a desired quantity of platelets or other blood component. Also, and what is very significant, the prior art methods and apparatus have often required the almost constant attention of an operator to make certain that proper separation was being effected in the separation chamber without contamination of one blood component with another blood component such as for example, red blood cells with platelet rich plasma.
As will be described in greater detail hereinafter, the present invention differs from the previously proposed methods and apparatus by providing a method and apparatus which requires a minimum amount of time to separate blood components and collect a desired blood component such as platelets, which takes a minimum amount of whole blood from a donor in order to effect efficient separation, which is effective and efficient at separating the whole blood into its various components, particularly platelets, and which does not require the constant attention, manipulation and operation by an operator. With respect to the latter, the apparatus of the invention functions essentially automatically with very little operator intervention.